JP5742788B2 - Hybrid car - Google Patents

Description

  The present invention relates to a hybrid vehicle, and more particularly, to a hybrid vehicle including an engine capable of outputting power for traveling, a motor capable of inputting / outputting power for traveling, and a battery capable of exchanging electric power with the motor.

  Conventionally, in this type of hybrid vehicle, an engine, a first motor, a drive shaft coupled to an axle, an output shaft of the engine, and a rotating shaft of the first motor are connected to a ring gear, a carrier, and a sun gear. A vehicle that includes a distribution integration mechanism, a second motor having a rotation shaft connected to a drive shaft, and a battery that exchanges electric power with the first motor and the second motor, and that is based on a required torque of the drive shaft while the engine is stopped. The engine and the first motor so that the required torque is output to the drive shaft while the required power is output from the engine until the required power reaches the second threshold value that is smaller than the first threshold value. And the second motor are controlled, and when the required power reaches the second threshold value or less during operation of the engine, the engine is stopped until the required power reaches the first threshold value or more. Is is the requested torque state has been proposed for controlling the engine and the first motor and the second motor so as to be output to the drive shaft (e.g., see Patent Document 1). In this hybrid vehicle, intermittent engine operation is performed so that the efficiency of the entire vehicle is improved by setting a value near the lower limit power at which the engine can be operated relatively efficiently as the first threshold value. Yes.

JP 2007-131103 A

  In such a hybrid vehicle, when the engine, the first motor, and the second motor are controlled so that the required torque is output to the drive shaft while the required power is output from the engine, the required torque is reduced with the engine stopped. When the engine, the first motor, and the second motor are controlled so as to be output to the drive shaft, the latter tends to increase the charge / discharge power of the battery. When the battery is not deteriorated, there is no particular problem. However, when the battery is being deteriorated, if the battery is charged and discharged with a large amount of power, the deterioration may be further advanced.

  The main purpose of the hybrid vehicle of the present invention is to suppress the progress of battery deterioration.

  The hybrid vehicle of the present invention employs the following means in order to achieve the main object described above.

The hybrid vehicle of the present invention
Based on an engine capable of outputting power for traveling, a motor capable of inputting / outputting power for traveling, a battery capable of exchanging electric power with the motor, and a required torque required for traveling while the engine is stopped When the required power required for the vehicle reaches or exceeds the starting threshold value, the engine is driven with the required torque while the required power is output from the engine until the required power reaches a stop threshold value that is smaller than the starting threshold value. The engine and the motor are controlled, and when the required power reaches the stop threshold or less during operation of the engine, the engine is stopped until the required power reaches the start threshold or more. A hybrid vehicle comprising control means for controlling the engine and the motor so as to travel with the required torque Oite,
The threshold for stopping is set to be smaller when the degree of deterioration of the battery exceeds the threshold than when the degree of deterioration of the battery is equal to or less than the threshold.
This is the gist.

  In the hybrid vehicle of the present invention, when the battery degradation level exceeds the threshold value, the stop threshold value is set to be smaller than when the battery degradation level is less than or equal to the threshold value. As a result, when the battery degradation level exceeds the threshold value, the engine is less likely to be shut down during engine operation than when the battery degradation level is less than or equal to the threshold value. Can be suppressed. As a result, the progress of battery deterioration can be suppressed.

  In such a hybrid vehicle of the present invention, the stop threshold value may be set so as to decrease as the degree of deterioration of the battery exceeds the threshold value. In this way, the progress of battery deterioration can be more appropriately suppressed.

  In the hybrid vehicle of the present invention, the starting threshold value is set to be smaller when the degree of deterioration of the battery exceeds the threshold value than when the degree of deterioration of the battery is equal to or less than the threshold value. It can also be. In this case, the stop threshold value may be set so as to decrease as the degree of deterioration of the battery increases beyond the threshold value. In this way, the progress of battery deterioration can be more appropriately suppressed.

  Furthermore, in the hybrid vehicle of the present invention, the control means is a means for setting the required power based on the required torque and the charge / discharge required power of the battery, and the charge / discharge required power is a deterioration of the battery. When the degree exceeds the threshold value, the battery may be set to be smaller as an absolute value than when the battery deterioration degree is equal to or less than the threshold value. In this way, the progress of battery deterioration can be more appropriately suppressed.

  Alternatively, in the hybrid vehicle of the present invention, the degree of deterioration of the battery is such that it is calculated by dividing the amount of change in the storage rate of the battery for a predetermined time by the integrated value of the charge / discharge power of the battery for a predetermined time. Can also be.

  In addition, in the hybrid vehicle of the present invention, the control means may be configured such that when the required power reaches or exceeds the start threshold value or the battery charge ratio is equal to or less than the start charge ratio threshold value while the engine is stopped. The engine is controlled so that the engine is started, and during operation of the engine, the storage ratio of the battery is equal to or greater than the stop storage ratio threshold greater than the start storage ratio threshold, and the required power is the stop power. It may be a means for controlling the engine to be shut down when it reaches a threshold value or less.

  In the hybrid vehicle of the present invention, three rotating elements are connected to a generator capable of exchanging electric power with the battery, a drive shaft connected to an axle, an output shaft of the engine, and a rotating shaft of the generator. And the planetary gear. The motor may be configured such that a rotary shaft is connected to the drive shaft.

1 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 20 as an embodiment of the present invention. It is a flowchart which shows an example of the drive control routine performed by HVECU70 of an Example. It is explanatory drawing which shows an example of the map for request | requirement torque setting. 4 is an explanatory diagram showing an example of a collinear diagram showing a dynamic relationship between the rotational speed and torque in the rotating element of the planetary gear 30 when the engine 22 is started. FIG. It is explanatory drawing which shows an example of the operating line of the engine 22, and a mode that the target rotational speed Ne * and the target torque Te * are set. 4 is an explanatory diagram showing an example of a collinear diagram showing a dynamic relationship between the number of rotations and torque in a rotating element of the planetary gear 30 when traveling while outputting power from the engine 22. FIG. It is a flowchart which shows an example of the value setting routine for control performed by HVECU70 of an Example. It is explanatory drawing which shows an example of the map for a correction coefficient setting. It is explanatory drawing which shows an example of the map for temporary charging / discharging request | requirement power setting. It is explanatory drawing which shows an example of the threshold value for temporary start / stop threshold setting. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 120 according to a modification. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 220 of a modified example. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 320 of a modified example. FIG. 11 is a configuration diagram showing an outline of a configuration of a hybrid vehicle 420 according to a modification.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIG. 1 is a configuration diagram showing an outline of the configuration of a hybrid vehicle 20 as an embodiment of the present invention. As shown in the drawing, the hybrid vehicle 20 of the embodiment includes an engine 22 that outputs power using gasoline or light oil as a fuel, an engine electronic control unit (hereinafter referred to as an engine ECU) 24 that controls the drive of the engine 22, an engine, and the like. A planetary gear 30 having a carrier connected to the crankshaft 26 and a ring gear connected to a drive shaft 36 connected to drive wheels 38a and 38b via a differential gear 37, and a rotor configured as a synchronous generator motor, for example. Motor MG1 connected to the sun gear of planetary gear 30, for example, a motor MG2 configured as a synchronous generator motor and having a rotor connected to drive shaft 36, inverters 41 and 42 for driving motors MG1 and MG2, Inverters 41 and 42 not shown A motor electronic control unit (hereinafter referred to as a motor ECU) 40 that drives and controls the motors MG1 and MG2 by switching the elements, and a motor MG1, configured as, for example, a lithium ion secondary battery via inverters 41 and 42. A battery 50 that exchanges power with the MG 2, a battery electronic control unit (hereinafter referred to as a battery ECU) 52 that manages the battery 50, and a hybrid electronic control unit (hereinafter referred to as a HVECU) 70 that controls the entire vehicle. Prepare.

  Although not shown, the engine ECU 24 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. . The engine ECU 24 receives signals from various sensors that detect the operating state of the engine 22, for example, a water temperature sensor that detects the crank position θcr from the crank position sensor that detects the rotational position of the crankshaft 26 and the coolant temperature of the engine 22. From the cam position sensor for detecting the cooling water temperature Tw from the cylinder, the in-cylinder pressure Pin from the pressure sensor installed in the combustion chamber, the rotational position of the intake valve for intake and exhaust to the combustion chamber and the camshaft for opening and closing the exhaust valve Position θca, throttle position TP from a throttle valve position sensor that detects the position of the throttle valve, intake air amount Qa from an air flow meter attached to the intake pipe, intake air temperature Ta from a temperature sensor also attached to the intake pipe, Installed in the exhaust system The air-fuel ratio AF from the air-fuel ratio sensor and the oxygen signal O2 from the oxygen sensor attached to the exhaust system are input via the input port, and the engine ECU 24 is for driving the engine 22. Various control signals, such as the drive signal to the fuel injection valve, the drive signal to the throttle motor that adjusts the throttle valve position, the control signal to the ignition coil integrated with the igniter, and the opening / closing timing of the intake valve can be changed A control signal to the variable valve timing mechanism is output via the output port. The engine ECU 24 is in communication with the HVECU 70, controls the operation of the engine 22 by a control signal from the HVECU 70, and outputs data related to the operation state of the engine 22 to the HVECU 70 as necessary. The engine ECU 24 also calculates the rotational speed of the crankshaft 26, that is, the rotational speed Ne of the engine 22 based on a signal from a crank position sensor (not shown) attached to the crankshaft 26.

  Although not shown, the motor ECU 40 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. . The motor ECU 40 receives signals necessary for driving and controlling the motors MG1 and MG2, for example, rotational positions θm1 and θm2 from rotational position detection sensors 43 and 44 that detect the rotational positions of the rotors of the motors MG1 and MG2, and not shown. A phase current applied to the motors MG1 and MG2 detected by the current sensor is input via the input port, and the motor ECU 40 outputs a switching control signal to switching elements (not shown) of the inverters 41 and 42. It is output through the port. The motor ECU 40 is in communication with the HVECU 70, controls the driving of the motors MG1 and MG2 by a control signal from the HVECU 70, and outputs data related to the operating state of the motors MG1 and MG2 to the HVECU 70 as necessary. The motor ECU 40 also calculates the rotational angular velocities ωm1, ωm2 and the rotational speeds Nm1, Nm2 of the motors MG1, MG2 based on the rotational positions θm1, θm2 of the rotors of the motors MG1, MG2 from the rotational position detection sensors 43, 44. ing.

  Although not shown, the battery ECU 52 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. . The battery ECU 52 is attached to a signal necessary for managing the battery 50, for example, an inter-terminal voltage Vb from a voltage sensor 51a installed between terminals of the battery 50 or an electric power line connected to an output terminal of the battery 50. The charging / discharging current Ib from the current sensor 51b, the battery temperature Tb from the temperature sensor 51c attached to the battery 50, and the like are input, and data relating to the state of the battery 50 is transmitted to the HVECU 70 by communication as necessary. . Further, the battery ECU 52 is a ratio of the capacity of electric power that can be discharged from the battery 50 at that time based on the integrated value of the charge / discharge current Ib detected by the current sensor 51b in order to manage the battery 50. The storage ratio SOC is calculated, and input / output limits Win and Wout, which are allowable input / output powers that may charge / discharge the battery 50, are calculated based on the calculated storage ratio SOC and the battery temperature Tb. The input / output limits Win and Wout of the battery 50 are set to the basic values of the input / output limits Win and Wout based on the battery temperature Tb, and the output limiting correction coefficient and the input limiting limit are set based on the storage ratio SOC of the battery 50. It can be set by setting a correction coefficient and multiplying the basic value of the set input / output limits Win and Wout by the correction coefficient.

  Although not shown, the HVECU 70 is configured as a microprocessor centered on a CPU, and includes a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port in addition to the CPU. The HVECU 70 includes an ignition signal from the ignition switch 80, a shift position SP from the shift position sensor 82 that detects the operation position of the shift lever 81, and an accelerator opening degree from the accelerator pedal position sensor 84 that detects the amount of depression of the accelerator pedal 83. Acc, the brake pedal position BP from the brake pedal position sensor 86 that detects the depression amount of the brake pedal 85, the vehicle speed V from the vehicle speed sensor 88, and the like are input via the input port. As described above, the HVECU 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via the communication port, and exchanges various control signals and data with the engine ECU 24, the motor ECU 40, and the battery ECU 52.

  In the hybrid vehicle 20 of the embodiment thus configured, the required torque Tr * to be output to the drive shaft 36 is calculated based on the accelerator opening Acc and the vehicle speed V corresponding to the depression amount of the accelerator pedal by the driver. The operation of the engine 22, the motor MG1, and the motor MG2 is controlled so that the required power corresponding to the required torque Tr * is output to the drive shaft 36. As the operation control of the engine 22, the motor MG1, and the motor MG2, the operation of the engine 22 is controlled so that the power corresponding to the required power is output from the engine 22, and all the power output from the engine 22 is transmitted to the planetary gear 30 and the motor. The torque conversion operation mode in which the motor MG1 and the motor MG2 are driven and controlled so that the torque is converted by the MG1 and the motor MG2 and output to the drive shaft 36, and the sum of the required power and the power required for charging and discharging the battery 50 is met. Operation of the engine 22 is controlled so that power is output from the engine 22, and all or part of the power output from the engine 22 with charge / discharge of the battery 50 is torque generated by the planetary gear 30, the motor MG1, and the motor MG2. The required power is output to the drive shaft 36 with conversion. Charge-discharge drive mode for driving and controlling the motors MG1 and MG2, there is a motor operation mode in which operation control to output a power commensurate to stop the operation of the engine 22 to the required power from the motor MG2 to the drive shaft 36. The torque conversion operation mode and the charge / discharge operation mode are modes in which the engine 22, the motor MG1, and the motor MG2 are controlled so that the required power is output to the drive shaft 36 with the operation of the engine 22. Since there is no substantial difference in control, both are hereinafter referred to as the engine operation mode.

  Next, the operation of the thus configured hybrid vehicle 20 of the embodiment will be described. FIG. 2 is a flowchart illustrating an example of a drive control routine executed by the HVECU 70 of the embodiment. This routine is repeatedly executed every predetermined time (for example, every several msec).

  When the drive control routine is executed, the HVECU 70 first stores the accelerator opening degree Acc from the accelerator pedal position sensor 84, the vehicle speed V from the vehicle speed sensor 88, the rotational speeds Nm1, Nm2 of the motors MG1, MG2, and the storage ratio of the battery 50. The SOC, the input / output limits Win, Wout, the charge / discharge required power Pb *, the start threshold value Pstart used for determining whether or not the engine 22 is to be started when the engine 22 is stopped, and the operation of the engine 22 during the operation of the engine 22 Data necessary for control, such as a stop threshold value Pstop used for determining whether to stop or not, is input (step S100). Here, the rotational speeds Nm1, Nm2 of the motors MG1, MG2 are calculated from the motor ECU 40 based on the rotational positions θm1, θm2 of the rotors of the motors MG1, MG2 detected by the rotational position detection sensors 43, 44. The input was made by communication. Further, the storage rate SOC of the battery 50 is calculated from the integrated value of the charge / discharge current Ib detected by the current sensor 51b and input from the battery ECU 52 by communication. The input / output limits Win and Wout of the battery 50 are set based on the battery temperature Tb of the battery 50 detected by the temperature sensor 51c and the storage ratio SOC of the battery 50, and are input from the battery ECU 52 by communication. . The charge / discharge required power Pb *, the start threshold value Pstart, and the stop threshold value Pstop of the battery 50 are set by a control value setting routine described later and written in a RAM (not shown). It should be noted that the input / output limits Win and Wout and the charge / discharge required power Pb * of the battery 50 are positive values on the side discharged from the battery 50.

  When the data is input in this way, the required torque Tr * required for traveling (to be output to the drive shaft 36) is set based on the input accelerator opening Acc and the vehicle speed V, and the drive shaft is set to the set required torque Tr *. A traveling power Pdrv * required for traveling is calculated by multiplying the rotational speed Nr of 36 (for example, the rotational speed Nm2 of the motor MG2 or the rotational speed obtained by multiplying the vehicle speed V by a conversion factor) (step S110). The required power Pe * required for the vehicle (to be output from the engine 22) is calculated by subtracting the charge / discharge required power Pb * of the battery 50 from the calculated traveling power Pdrv * (step S120). Here, in the embodiment, the required torque Tr * is stored in a ROM (not shown) as a required torque setting map by predetermining the relationship among the accelerator opening Acc, the vehicle speed V, and the required torque Tr *. When Acc and vehicle speed V are given, the corresponding required torque Tr * is derived and set from the stored map. An example of the required torque setting map is shown in FIG.

  Subsequently, it is determined whether the engine 22 is operating or stopped (step S130), and when it is determined that the engine 22 is stopped, the required power Pe * is compared with the starting threshold value Pstart. At the same time (step S140), the storage ratio SOC of the battery 50 is compared with the starting threshold value Sstart (step S150). Here, the starting threshold value Sstart is defined as the upper limit of the range of the power storage rate SOC that should be shifted to running in the engine operation mode in order to suppress overdischarge of the battery 50. For example, 35%, 37%, and 40% Etc. can be used. The processes in steps S140 and S150 are processes for determining whether or not the engine 22 start condition is satisfied.

  When the required power Pe * is less than the start threshold value Pstart and the storage ratio SOC of the battery 50 is greater than the start threshold value Sstart, it is determined that the start condition of the engine 22 is not satisfied, and the torque command Tm1 * of the motor MG1 has a value. 0 is set (step S160), the required torque Tr * is set to a temporary torque Tm2tmp as a temporary value of the torque to be output from the motor MG2 (step S170), and the input / output limits Win and Wout of the battery 50 are set to the motor MG2. The torque limits Tm2min and Tm2max are calculated as upper and lower limits of the torque that may be output from the motor MG2 by dividing by the rotation speed Nm2 (step S180), and the temporary torque Tm2tmp is torqued as shown in the following equation (1). Should be output from motor MG2 with limits Tm2min and Tm2max Setting the torque command Tm2 * as a torque (step S190).

  Tm2 * = max (min (Tm2tmp, Tm2max), Tm2min) (1)

  When the torque commands Tm1 * and Tm2 * for the motors MG1 and MG2 are thus set, the set torque commands Tm1 * and Tm2 * for the motors MG1 and MG2 are transmitted to the motor ECU 40 (step S200), and this routine is terminated. Receiving the torque commands Tm1 * and Tm2 * of the motors MG1 and MG2, the motor ECU 40 controls the switching elements (not shown) of the inverters 41 and 42 so that the motors MG1 and MG2 are driven by the torque commands Tm1 * and Tm2 *. . By such control, it is possible to travel by outputting the required torque Tr * (travel power Pdrv *) to the drive shaft 36 within the range of the input / output limits Win and Wout of the battery 50 in the motor operation mode.

  When the required power Pe * is greater than or equal to the start threshold value Pstart in step S140, or when the storage ratio SOC of the battery 50 is less than or equal to the start threshold value Sstart in step S150, it is determined that the start condition of the engine 22 is satisfied, and the engine 22 is started (step S210). FIG. 4 is an explanatory diagram showing an example of a collinear diagram showing a dynamic relationship between the rotational speed and torque in the rotating element of the planetary gear 30 when the engine 22 is started. In the figure, the left S-axis indicates the rotation speed of the sun gear 31 that is the rotation speed Nm1 of the motor MG1, the C-axis indicates the rotation speed of the carrier 34 that is the rotation speed Ne of the engine 22, and the R-axis indicates the rotation speed of the motor MG2. The rotation speed Nr of the ring gear 32, which is a number Nm2, is shown. Further, two thick arrows on the R axis indicate torque output from the motor MG1 and acting on the drive shaft 36, and torque output from the motor MG2 and acting on the drive shaft 36. The engine 22 is started by outputting a torque for cranking the engine 22 from the motor MG1, and outputting a cancel torque for canceling the torque acting on the drive shaft 36 in accordance with the output of the torque from the motor MG2. Is performed by cranking the engine 22 and starting fuel injection control or ignition control when the rotational speed Ne of the engine 22 reaches a predetermined rotational speed (for example, 1000 rpm). During the start of the engine 22, the drive control of the motor MG2 is performed so that the required torque Tr * is output to the drive shaft 36 within the range of the input / output limits Win and Wout of the battery 50. That is, the torque to be output from the motor MG2 (temporary torque Tm2tmp) is the sum of the required torque Tr * and the cancel torque.

  When the engine 22 is started, the target rotational speed Ne * and the target torque Te * as operating points at which the engine 22 should be operated based on the required power Pe * and an operation line (for example, a fuel efficiency operation line) for operating the engine 22 efficiently. Are set (step S240). An example of the operation line of the engine 22 and how the target rotational speed Ne * and the target torque Te * are set are shown in FIG. As shown in the figure, the target rotational speed Ne * and the target torque Te * can be obtained as an intersection of the operation line and a curve having a constant required power Pe * (Ne * × Te *).

  Subsequently, using the target rotational speed Ne * of the engine 22, the rotational speed Nm2 of the motor MG2, and the gear ratio ρ of the planetary gear 30, the target rotational speed Nm1 * of the motor MG1 is calculated and calculated by the following equation (2). Based on the target rotational speed Nm1 * of MG1 and the current rotational speed Nm1, torque command Tm1 * of motor MG1 is calculated by equation (3) (step S250). Expression (2) is a dynamic relational expression for the rotating element of the planetary gear 30. FIG. 6 shows an example of a collinear diagram showing the dynamic relationship between the rotational speed and torque of the rotating element of the planetary gear 30 when traveling while outputting power from the engine 22. Equation (2) can be easily derived by using this alignment chart. Expression (3) is a relational expression in feedback control for rotating the motor MG1 at the target rotational speed Nm1 *. In Expression (3), “k1” in the second term on the right side is a gain of the proportional term. “K2” in the third term on the right side is the gain of the integral term.

Nm1 * = Ne * ・ (1 + ρ) / ρ-Nm2 / ρ (2)
Tm1 * =-ρ ・ Te * / (1 + ρ) + k1 (Nm1 * -Nm1) + k2∫ (Nm1 * -Nm1) dt (3)

  Next, as shown in the following equation (4), the torque command Tm1 * of the motor MG1 divided by the gear ratio ρ (number of teeth of the sun gear / number of teeth of the ring gear) of the planetary gear 30 is added to the required torque Tr *. The temporary torque Tm2tmp of the motor MG2 is set (step S260). As shown in the equations (5) and (6), from the input / output limits Win and Wout of the battery 50, the torque command Tm1 * of the motor MG1 is changed to the current motor MG1. A value obtained by multiplying the number of revolutions Nm1 by subtracting the power consumption (generated power) of the motor MG1 is divided by the number of revolutions Nm2 of the motor MG2, and torque limits Tm2min and Tm2max of the motor MG2 are calculated (step S270). As shown in Expression (1), the temporary torque Tm2tmp is limited by the torque limits Tm2min and Tm2max, and the torque command of the motor MG2 is set. Setting the m2 * (step S280). Here, equation (4) can be easily derived from the alignment chart of FIG.

Tm2tmp = Tr * + Tm1 * / ρ (4)
Tm2min = (Win-Tm1 * ・ Nm1) / Nm2 (5)
Tm2max = (Wout-Tm1 * ・ Nm1) / Nm2 (6)

  Then, the target rotational speed Ne * and the target torque Te * of the engine 22 are transmitted to the engine ECU 24, and the torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 are transmitted to the motor ECU 40 (step S290), and this routine is terminated. To do. The engine ECU 24 that has received the target rotational speed Ne * and the target torque Te * of the engine 22 sucks in the engine 22 so that the engine 22 is operated at the operating point indicated by the target rotational speed Ne * and the target torque Te *. Controls such as air volume control, fuel injection control, and ignition control are performed. Receiving the torque commands Tm1 * and Tm2 * of the motors MG1 and MG2, the motor ECU 40 controls the switching elements (not shown) of the inverters 41 and 42 so that the motors MG1 and MG2 are driven by the torque commands Tm1 * and Tm2 *. . By such control, it is possible to travel by outputting the required torque Tr * (travel power Pdrv *) to the drive shaft 36 within the range of the input / output limits Win and Wout of the battery 50 in the engine operation mode.

  When running in the engine operation mode is started in this way, the next time this routine is executed, it is determined in step S130 that the engine 22 is in operation. Therefore, the required power Pe * is set to a stop threshold value smaller than the start threshold value Pstart. While comparing with Pstop (step S220), the storage ratio SOC of the battery 50 is compared with a stop threshold Sstop larger than the start threshold Start (step S230). Here, as the stop threshold Sstop, for example, 45%, 47%, 50%, or the like can be used. The processes in steps S220 and S230 are processes for determining whether or not the engine 22 stop condition is satisfied.

  When the required power Pe * is greater than the stop threshold value Pstop or when the storage ratio SOC of the battery 50 is less than the threshold value Sstop, it is determined that the stop condition of the engine 22 is not satisfied, and the battery 50 is turned on in the engine operation mode. Set target engine speed Ne * and target torque Te * of engine 22 and torque commands Tm1 * and Tm2 * of motors MG1 and MG2 so that required torque Tr * is output to drive shaft 36 within the limits of output limits Win and Wout. And it transmits to engine ECU24 and motor ECU40 (steps S240-S290), and this routine is ended.

  On the other hand, when the required power Pe * is equal to or lower than the stop threshold value Pstop and the storage ratio SOC of the battery 50 is equal to or higher than the stop threshold value Sstop, it is determined that the stop condition of the engine 22 is satisfied, and the operation of the engine 22 is stopped. (Step S300) In the motor operation mode, torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 are set so that the required torque Tr * is output to the drive shaft 36 within the range of the input / output limits Win and Wout of the battery 50. And it transmits to motor ECU40 (step S160-S200), and this routine is complete | finished.

  The drive control routine of FIG. 2 has been described above. Next, processing for setting the charge / discharge required power Pb *, the start threshold Pstart, and the stop threshold Pstop of the battery 50 by the control value setting routine illustrated in FIG. 7 will be described. This routine is repeatedly executed by the HVECU 70 every predetermined time (for example, every several msec).

  When the control value setting routine is executed, the HVECU 70 first stores the vehicle speed V, the storage ratio SOC of the battery 50, the storage ratio of the battery 50 for a predetermined time (for example, 0.5 seconds, 1 second, 1.5 seconds, etc.). A process of inputting data such as a predetermined amount of electricity storage rate change amount ΔSOC that is a change amount of SOC and a predetermined amount of battery work amount Wb that is a work amount of the battery 50 for a predetermined time is executed (step S400). Here, the input method of the vehicle speed V and the power storage ratio SOC has been described above. The predetermined amount of electricity storage rate change ΔSOC is calculated by subtracting the electricity storage rate SOC calculated a predetermined time before the power storage rate SOC calculated last (latest) from the battery ECU 52 via communication. . The battery work amount Wb for a predetermined time is the charge / discharge power (Vb × Ib) of the battery 50 as a product of the voltage Vb between the terminals of the battery 50 from the voltage sensor 51a and the charge / discharge current Ib of the battery 50 from the current sensor 51b. A value calculated as an integrated value from a predetermined time before to the present (latest) is input from the battery ECU 52 by communication.

  When the data is input in this way, the deterioration degree value D as a value indicating the degree of deterioration of the battery 50 is calculated by dividing the input predetermined time power storage ratio change amount ΔSOC by the predetermined time battery work amount Wb (step S410). Generally, when the battery 50 deteriorates, the battery 50 tends to have a large change in the storage ratio SOC with respect to the same work amount. Therefore, the deterioration degree value D increases as the deterioration of the battery 50 progresses.

  When the deterioration degree value D is thus calculated, based on the calculated deterioration degree value D, the correction coefficient Kp used for the setting process of the charge / discharge required power Pb * of the battery 50 and the setting process of the starting threshold value Pstart and the stopping threshold value Pstop is calculated. It sets (step S420). Here, the correction coefficient Kp is stored in a ROM (not shown) as a correction coefficient setting map by predetermining the relationship between the deterioration degree value D and the correction coefficient Kp in the embodiment, and given the deterioration degree value D. The corresponding correction coefficient Kp is derived and set from the stored map. An example of the correction coefficient setting map is shown in FIG. In the figure, “Dref” is an allowable upper limit value of the deterioration degree value D (deterioration degree of the battery 50) (upper limit value in the range of the deterioration degree value D that can be considered that the battery 50 is not deteriorated). Or a value determined in advance by analysis or the like can be used. As shown in the figure, the correction coefficient Kp is set to a value 1 when the deterioration degree value D is less than or equal to the allowable upper limit value Dref, and from the value 1 as the deterioration degree value D is larger when the deterioration degree value D is larger than the allowable upper limit value Dref. It tends to be smaller.

  Subsequently, based on the storage ratio SOC of the battery 50, a temporary charge / discharge required power Pbtmp as a temporary value of the charge / discharge required power Pb * is set (step S430). Here, the temporary charging / discharging required power Pbtmp is stored in a ROM (not shown) as a temporary charging / discharging required power setting map by predetermining the relationship between the storage ratio SOC of the battery 50 and the temporary charging / discharging required power Pbtmp in the embodiment. It is assumed that the provisional charge / discharge required power Pbtmp is derived and set from the stored map when the storage ratio SOC is given. An example of the temporary charge / discharge required power setting map is shown in FIG. As shown in the drawing, when the power storage rate SOC is the target rate SOC * (for example, 55%, 60%, 65%, etc.), the value 0 is set as the temporary charge / discharge required power Pbtmp. When the power storage rate SOC is greater than the target rate SOC *, the larger the power storage rate SOC until the power storage rate SOC reaches a rate Shi greater than the target rate SOC *, the more positive predetermined power Pdis (for example, +2 kW, +3 kW, +5 kW, etc.) When the power storage ratio SOC is larger than the ratio Sh, the predetermined power Pdis is set as the temporary charge / discharge required power Pbtmp. On the other hand, when the power storage ratio SOC is smaller than the target ratio SOC *, the smaller the power storage ratio SOC until the power storage ratio SOC reaches a ratio Slo smaller than the target ratio SOC *, the negative predetermined power Pch (for example, −2 kW, −3 kW, 5 kW) When the power storage rate SOC is smaller than the rate Slo, the predetermined power Pch is set as the temporary charge / discharge required power Pbtmp.

  When the temporary charge / discharge required power Pbtmp is set in this way, the charge / discharge required power Pb * of the battery 50 is set by multiplying the set temporary charge / discharge required power Pbtmp by the correction coefficient Kp (step S440). When the engine 22 is running in the engine operation mode, the power storage ratio SOC of the battery 50 can be brought close to the target ratio SOC * by operating the engine 22 with the required power Pe * corresponding to the charge / discharge required power Pb *. Further, by multiplying the temporary charge / discharge required power Pbtmp by the correction coefficient Kp and setting the charge / discharge required power Pb *, when the deterioration degree value D is larger than the allowable upper limit value Dref, the deterioration degree value D is equal to or lower than the allowable upper limit value Dref. The absolute value of the charging / discharging power of the battery 50 can be made smaller than in this case, and the progress of the deterioration of the battery 50 can be suppressed. In addition, when the deterioration degree value D is larger than the allowable upper limit value Dref, the correction coefficient Kp is set so as to decrease as the deterioration degree value D increases. That is, the absolute value decreases as the deterioration degree value D increases. By setting the power Pb *, the progress can be more appropriately suppressed according to the degree of deterioration of the battery 50.

  Next, based on the vehicle speed V, a temporary start threshold value Pstarttmp and a temporary stop threshold value Pstoptmp are set as temporary values of the start threshold value Pstart and the stop threshold value Pstop (step S450). Here, the temporary start threshold value Pstarttmp and the temporary stop threshold value Pstoptmp are set in the embodiment by setting the relationship between the vehicle speed V and the temporary start threshold value Pstarttmp and the temporary stop threshold value Pstoptmp in advance through experiments or the like. The map is stored in a ROM (not shown) as a work map, and when the vehicle speed V is given, the corresponding temporary start threshold value Pstarttmp and temporary stop threshold value Pstoptmp are derived and set from the stored map. An example of the temporary start / stop threshold setting map is shown in FIG. As shown in the figure, the temporary start threshold value Pstarttmp and the temporary stop threshold value Pstoptmp are smaller than the temporary start threshold value Pstarttmp with respect to the same vehicle speed V and smaller as the vehicle speed V is higher. It was supposed to be set to a trend. The former is for avoiding frequent starting and stopping of the engine 22. In the latter case, when the vehicle speed V (the rotational speed Nm2 of the motor MG2) is high, the output (the rotational speed Nm2 × torque Tm2) of the motor MG2 increases, and the required torque Tr * (travel power) is increased only by the output from the motor MG2. This is because it is possible to cope with the required torque Tr * in consideration of the possibility that it may become impossible to cope with (Pr *).

  When the temporary start threshold value Pstarttmp and the temporary stop threshold value Pstoptmp are thus set, the correction coefficient Kp is set to the set temporary start threshold value Pstarttmp and the temporary stop threshold value Pstoptmp as shown in the following equations (7) and (8). Multiplication is performed to set a start threshold value Pstart and a stop threshold value Pstop (step S460), and this routine is terminated. The starting threshold value Pstart and the stopping threshold value Pstop set in this way are smaller values when the deterioration degree value D is larger than the allowable upper limit value Dref, compared with when the deterioration degree value D is less than or equal to the allowable upper limit value Dref. Hereinafter, the reason why the start threshold value Pstart and the stop threshold value Pstop are set in this way will be described.

Pstart = Kp ・ Pstarttmp (7)
Pstop = Kp ・ Pstoptmp (8)

  In general, when traveling in the motor operation mode, the required torque Tr * is output to the drive shaft 36 by driving the motor MG2 accompanied by discharge from the battery 50, and when traveling in the engine operation mode, the engine 22 is operated. The required torque Tr * is output to the drive shaft 36 by driving the motors MG1 and MG2 that accompany charging / discharging of the battery 50 as necessary. For this reason, when traveling in the motor operation mode, the absolute value of the charge / discharge power of the battery 50 tends to be larger than when traveling in the engine operation mode. In the embodiment, when the deterioration degree value D is larger than the allowable upper limit value Dref, the starting threshold value Pstart and the stopping threshold value Pstop are made smaller than when the deterioration degree value D is less than or equal to the allowable upper limit value Dref. The engine 22 is likely to be started when the engine 22 is stopped (it is easy to shift from the motor operation mode to the engine operation mode), and the operation of the engine 22 is less likely to be stopped while the engine 22 is operating (engine operation). It becomes difficult to shift from mode to motor operation mode). Thereby, it can suppress that the battery 50 is charged / discharged with big electric power, and can suppress that deterioration of the battery 50 advances. Further, by setting the start threshold value Pstart and the stop threshold value Pstop in this way, it is possible to suppress a decrease in the storage ratio SOC of the battery 50. As a result, when the operation of the engine 22 is stopped, the engine 22 must be started when the power storage rate SOC of the battery 50 reaches the start threshold Sstart or less even though the required power Pe * is less than the start threshold Pstart. Can be suppressed. Further, when the deterioration degree value D is larger than the allowable upper limit value Dref, the correction coefficient Kp is set so as to decrease as the deterioration degree value D increases, that is, the start threshold value Pstart and the stop threshold value Pstop are set in this tendency. The progress of the battery 50 can be suppressed more appropriately depending on the degree of deterioration of the battery 50. In addition, depending on the driver, for example, in the case of a driver who performs an accelerator operation so that the traveling power Pdrv * changes in the vicinity of the temporary start threshold Pstart or the temporary stop threshold Pstop, the engine 22 is started and stopped. Can be reduced in frequency. As a result, it is possible to save power required for starting the engine 22 and improve energy efficiency.

  According to the hybrid vehicle 20 of the embodiment described above, when the deterioration degree value D indicating the degree of deterioration of the battery 50 is larger than the allowable upper limit value Dref, compared to when the deterioration degree value D is less than or equal to the allowable upper limit value Dref, Since the start threshold value Pstart and the stop threshold value Pstop are set to small values, it is easy to travel in the engine operation mode, and it is possible to suppress the battery 50 from being charged and discharged with a large amount of electric power. Can be further prevented from proceeding.

  In the hybrid vehicle 20 of the embodiment, when the deterioration degree value D is larger than the allowable upper limit value Dref, the start threshold value Pstart and the stop threshold value Pstop are smaller values than when the deterioration degree value D is less than or equal to the allowable upper limit value Dref. However, the start threshold value Pstart is the same value (temporary start threshold value Pstart) regardless of the deterioration degree value D, and the stop threshold value Pstop is greater than the allowable upper limit value Dref. Alternatively, the deterioration degree value D may be a smaller value than when the deterioration degree value D is equal to or less than the allowable upper limit value Dref. Even in this case, it is difficult to stop the operation of the engine 22 during the operation of the engine 22 (it is difficult to shift from the engine operation mode to the motor operation mode), so that the battery 50 is prevented from being charged / discharged with large electric power. And further deterioration of the battery 50 can be suppressed.

  In the hybrid vehicle 20 of the embodiment, when the deterioration degree value D is larger than the allowable upper limit value Dref, the correction coefficient Kp is set so as to decrease as the deterioration degree value D increases. Any value can be used as long as the correction coefficient Kp is smaller than the value Dref. For example, a fixed value such as 0.5, 0.6, or 0.7 is set as the correction coefficient Kp. It is good also as what to do. That is, in the hybrid vehicle 20 of the embodiment, when the deterioration degree value D is larger than the allowable upper limit value Dref, the starting threshold value Pstart and the stopping threshold value Pstop are set so as to decrease as the deterioration degree value D increases. Alternatively, a value such as 0.5 times, 0.6 times, or 0.7 times the temporary start threshold value Pstarttmp or the temporary stop threshold value Pstoptmp may be set as the start threshold value Pstart or the stop threshold value Pstop.

  In the hybrid vehicle 20 of the embodiment, the temporary start threshold value Pstarttmp and the temporary stop threshold value Pstoptmp are set such that the higher the vehicle speed V, the lower the temporary start threshold value Pstarttmp and the temporary stop value. A fixed value may be set for each of the use threshold values Pstoptmp.

  In the hybrid vehicle 20 of the embodiment, the charge / discharge required power Pb * is set by multiplying the temporary charge / discharge required power Pbtmp by the correction coefficient Kp corresponding to the deterioration degree value D. However, the correction is performed regardless of the deterioration degree D. The temporary charge / discharge required power Pbtmp may be set to the charge / discharge required power Pb * as it is without using the coefficient Kp.

  In the hybrid vehicle 20 of the embodiment, the deterioration degree value D is calculated by dividing the amount of change ΔSOC for the predetermined time by the battery work amount Wb for the predetermined time. For example, the charge / discharge current Ib of the battery 50 is integrated over time. A plurality of combinations of the battery capacity Cb and the inter-terminal voltage Vb are plotted and the data is used by the least squares method with the battery capacity Cb as the x-axis and the inter-terminal voltage Vb of the battery 50 as the y-axis. An inclination (discharge characteristic) may be obtained, and a change amount of the discharge characteristic may be set as a deterioration degree value D.

  In the hybrid vehicle 20 of the embodiment, the power from the motor MG2 is output to the drive shaft 36. However, as illustrated in the hybrid vehicle 120 of the modified example of FIG. 11, the drive shaft 36 transmits the power from the motor MG2. It may be output to an axle (an axle connected to the wheels 39a and 39b in FIG. 11) different from the connected axle (the axle to which the drive wheels 38a and 38b are connected).

  In the hybrid vehicle 20 of the embodiment, the power from the engine 22 is output to the drive shaft 36 connected to the drive wheels 38a and 38b via the planetary gear 30, but is exemplified in the hybrid vehicle 220 of the modification of FIG. As described above, the inner rotor 232 connected to the crankshaft of the engine 22 and the outer rotor 234 connected to the drive shaft 36 that outputs power to the drive wheels 38a and 38b have a part of the power from the engine 22. A counter-rotor motor 230 that transmits power to the drive shaft 36 and converts remaining power into electric power may be provided.

  In the hybrid vehicle 20 of the embodiment, the power from the engine 22 is output to the drive shaft 36 connected to the drive wheels 38a and 38b via the planetary gear 30, and the power from the motor MG2 is output to the drive shaft 36. However, as illustrated in the hybrid vehicle 320 of the modified example of FIG. 13, the motor MG is attached to the drive shaft 36 connected to the drive wheels 38 a and 38 b via the transmission 330 and the clutch 329 is attached to the rotation shaft of the motor MG. The power from the engine 22 is output to the drive shaft 36 via the rotation shaft of the motor MG and the transmission 330, and the power from the motor MG is output to the drive shaft via the transmission 330. It is good also as what outputs to. Alternatively, as exemplified in the hybrid vehicle 420 of the modified example of FIG. 14, the power from the engine 22 is output to the drive shaft 36 connected to the drive wheels 38a and 38b via the transmission 430 and the power from the motor MG. May be output to an axle different from the axle to which the drive wheels 38a, 38b are connected (the axle connected to the wheels 39a, 39b in FIG. 14).

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the engine 22 corresponds to “engine”, the motor MG2 corresponds to “motor”, the battery 50 corresponds to “battery”, and the drive control routine of FIG. 2 and the control value setting routine of FIG. The HVECU 70 to be executed, the engine ECU 24 that receives the target rotational speed Ne * and the target torque Te * of the engine 22 from the HVECU 70, and controls the engine 22, and the torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 are received from the HVECU 70. The combination of the motor ECU 40 that controls the motors MG1 and MG2 corresponds to “control means”.

  Here, the “engine” is not limited to the engine 22 that outputs power using gasoline or light oil as a fuel, but any type of engine that can output power for traveling, such as a hydrogen engine. It does not matter. The “motor” is not limited to the motor MG2 configured as a synchronous generator motor, and may be any type of motor as long as it can input and output driving power, such as an induction motor. . The “battery” is not limited to the battery 50 configured as a lithium ion secondary battery, but can exchange power with the motor, such as a nickel hydride secondary battery, a nickel cadmium secondary battery, and a lead storage battery. Any type of battery may be used. The “control means” is not limited to the combination of the HVECU 70, the engine ECU 24, the motor ECU 40, and the battery ECU 52, and may be configured by a single electronic control unit. Further, as the “control means”, when the deterioration degree value D indicating the degree of deterioration of the battery 50 is larger than the allowable upper limit value Dref, the starting threshold value Pstart is compared to when the deterioration degree value D is equal to or lower than the allowable upper limit value Dref. The stop threshold value Pstop is not limited to a small value, and when the required power required for the vehicle based on the required torque required for traveling during the stoppage of the engine reaches the start threshold value or more. The engine and motor are controlled to run with the required torque while the required power is output from the engine until the required power falls below the stop threshold smaller than the start threshold, and the required power falls below the stop threshold during engine operation. When it reaches, the engine will stop running until the required power exceeds the threshold for starting, The engine and the motor are controlled so that the threshold value for stopping is set to be smaller when the battery deterioration level exceeds the threshold value, compared to when the battery deterioration level is equal to or lower than the threshold value. Anything can be used.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. Therefore, the elements of the invention described in the column of means for solving the problems are not limited. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problems. It is only a specific example.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

  The present invention can be used in the manufacturing industry of hybrid vehicles.

  20, 120, 220, 320, 420 Hybrid vehicle, 22 engine, 24 electronic control unit for engine (engine ECU), 26 crankshaft, 30 planetary gear, 36 drive shaft, 37 differential gear, 38a, 38b drive wheel, 39a, 39b Wheel, 40 Motor electronic control unit (motor ECU), 41, 42 Inverter, 43, 44 Rotation position detection sensor, 50 High voltage battery, 51a Voltage sensor, 51b Current sensor, 51c Temperature sensor, 52 Electronic control unit for battery ( Battery ECU), 54a High voltage system power line, 54b Low voltage system power line, 56 System main relay, 57 DC / DC converter, 58 Low voltage battery, 59 Auxiliary equipment, 60 Charger, 62 Relay, 64 DC / DC converter, 66 AC / DC converter, 68 power plug, 69 connection detection sensor, 70 hybrid electronic control unit (HVECU), 80 ignition switch, 81 shift lever, 82 shift position sensor, 83 accelerator pedal, 84 accelerator pedal position sensor , 85 Brake pedal, 86 Brake pedal position sensor, 88 Vehicle speed sensor, 230 Counter rotor motor, 232 Inner rotor, 234 Outer rotor, 329 Clutch, 330, 430 Transmission, MG, MG1, MG2 motor.

Claims (6)

Based on an engine capable of outputting power for traveling, a motor capable of inputting / outputting power for traveling, a battery capable of exchanging electric power with the motor, and a required torque required for traveling while the engine is stopped When the required power required for the vehicle reaches or exceeds the starting threshold value, the engine is driven with the required torque while the required power is output from the engine until the required power reaches a stop threshold value that is smaller than the starting threshold value. The engine and the motor are controlled, and when the required power reaches the stop threshold or less during operation of the engine, the engine is stopped until the required power reaches the start threshold or more. A hybrid vehicle comprising control means for controlling the engine and the motor so as to travel with the required torque Oite,
The stop threshold, when the degree of degradation of said battery exceeds a threshold, Ri degree of degradation of said battery is Na is set to be smaller than when: the threshold value
The control means is means for setting the required power based on the required torque and the charge / discharge required power of the battery,
The charge / discharge required power is set to be smaller as an absolute value when the degree of deterioration of the battery exceeds the threshold, compared to when the degree of deterioration of the battery is equal to or less than the threshold.
Hybrid car. The hybrid vehicle according to claim 1,
The stop threshold is set to be smaller as the degree of deterioration of the battery is larger than the threshold.
Hybrid car. A hybrid vehicle according to claim 1 or 2,
The starting threshold is set to be smaller when the degree of deterioration of the battery exceeds the threshold than when the degree of deterioration of the battery is equal to or less than the threshold.
Hybrid car. A hybrid vehicle according to claim 3,
The stop threshold is set to be smaller as the degree of deterioration of the battery is larger than the threshold.
Hybrid car. A hybrid vehicle according to any one of claims 1 to 4 ,
The degree of deterioration of the battery is a degree calculated by dividing the amount of change in the storage ratio of the battery over a predetermined time by the integrated value of the charge / discharge power of the battery over a predetermined time.
Hybrid car. A hybrid vehicle according to any one of claims 1 to 5 ,
A generator capable of exchanging power with the battery;
A planetary gear having three rotating elements connected to a driving shaft coupled to an axle, an output shaft of the engine, and a rotating shaft of the generator;
With
The motor has a rotation shaft connected to the drive shaft.
Hybrid car.

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